Xref: utzoo comp.misc:2239 comp.periphs:864
Path: utzoo!mnetor!uunet!pilchuck!ssc!markz
From: markz@ssc.UUCP (Mark Zenier)
Newsgroups: comp.misc,comp.periphs
Subject: Re: MFM encoding question
Message-ID: <1160@ssc.UUCP>
Date: 6 Apr 88 20:14:38 GMT
References: <752@ndsuvax.UUCP> <1140@ssc.UUCP> <768@ndsuvax.UUCP>
Organization: SSC, Inc., Seattle, WA
Lines: 31
Keywords: MFM
Summary: Followup

In article <768@ndsuvax.UUCP>, ncreed@ndsuvax.UUCP (Walter Reed) writes:
> Someone really needs to write a book on this subject, and if they have, I
> sure can't find it.  Hell, just a magazine article would help.  (I already
> checked for literiture locally available.  The Net is my last hope!)
> 
> I've gotten several replies just like the one above that basically say that
> the controller does it for you.  That's true for most machines out there,
> but not the amiga.  So, I still need this info!  Help! :-)
> 
> BTW, thanks to the people that already replied.

I've already emailed this Info but I'll waste some net bandwidth on it too.

In an Oem manual for a Memorex 550 8 inch drive they gave references to the
IBM documents for what is now the standard MFM encoding.
The titles are not exact, and these are 10 years old, but the real stuff.

GA21-9190-3 Diskette General Information
GA21-9190-3 Single Sided OEM information
GA21-9257-1 Double Sided OEM information

Try the local IBM mainframe sales office and see if they have a manual
library that will sell to the general public. The seattle office used to.

The above mentioned Memorex manual had everything on the formats also, like
the bit sequence of the address marks, which deliberatly violate the MFM
encoding rules.  Find someone with an old heathkit H-11 computer with 
floppydisks, or try some of the other disk manufacturers, as (I think) memorex
quit this business a couple of years ago.

Mark Zenier